The present invention relates to communication networks, and, more particularly, to associating packets with services in communication networks.
In general, communication service providers obtain revenue by providing services. It is desirable, therefore, for service providers to offer multiple services to a customer over a single physical access link. In many cases, some type of tag may be used to differentiate packets between the multitude of services.
Various techniques may be used to mark or tag packets to allow for service differentiation. The Internet Protocol (IP) defines several fields within a packet, which may be used to carry a class of service marking. The type of service (TOS) and diffserve codepoint (DSCP) fields, for example, may be used to differentiate various qualities of service groupings across the network. The IEEE 802.1Q specification defines Virtual LAN (VLAN) fields, which may be used to associate packets with a particular VLAN, i.e., a group of computers and other network resources that behave as if they were connected to a single network segment. Multi-protocol Label Switching (MPLS) also provides for placement of tags on packets to differentiate multiple traffic flows.
In the foregoing examples, a named field in a packet may be used to provide explicit service differentiation based on the packet contents. Customer equipment may be capable of including such markings or tags in the packets to allow for service classification and differentiation based on these markings and/or tags. Unfortunately, less sophisticated customer equipment may not be able to insert the markings and/or tags in the packets. For example, less sophisticated hubs and/or routers may be able to forward packets, but not mark and/or tag them.